Issued  Dec.  1, 1910. 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 

BUREAU  OF  SOILS. 


IMPORTANT  SOILS 


OF  THE 


UNITED  STATES. 


ISSUED  TO  ACCOMPANY 'A  COLLECTION  OF 
SOILS  AND  SUBSOILS  (IN  13  BOXES)  FOR 
USE  OF  SCHOOLS  AND  COLLEGES  TEACHING 
AGRICULTURE  AND  PHYSICAL  GEOGRAPHY. 


WASHINGTON: 

GOVERNMENT  PRINTING  OttlQX. 
Ifllfl. 


Issued  Dec.  1, 1916. 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 

BUREAU  OF  SOILS. 


IMPORTANT  SOILS 

OF  THE 

UNITED  STATES. 


ISSUED  TO  ACCOMPANY  A  COLLECTION  OF 
SOILS  AND  SUBSOILS  (IN  13  BOXES)  FOR 
USE  OF  SCHOOLS  AND  COLLEGES  TEACHING 
AGRICULTURE  AND  PHYSICAL  GEOGRAPHY. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 
1916. 


SOIL  PROVINCES  AND  SOIL  REGIONS 
OF  THE  UNITED  STATES 


LEGEND 


Soil  Provinces 

i     Appalachian  Mountain 
and  Plateau 


B  Atlantic  and  Gulf  Coastal  Plain 

c     I  Glacial  and  Loessial 

^El  Glacial  Lake  and  River  Terrace 

]  Limestone  Valley  and  Upland 

f     I  Piedmont  Plateau 

Bi  River  Flood  Plain 


Soil  Regions 

' H     1     Great  Basin 

I      '      I      Great  Plains 

Northwest  Intermountain 
I     K     i     Pacific  Coast 

Rocky  Mountain 
I     M  Arid  Southwest 


SOIL   PROVINCES. 

Page. 

Appalachian  Mountain  and  Plateau 10 

Atlantic  and  Gulf  Coastal  Plain 7 

Glacial  and  Loessial 5 

Glacial  Lake  and  River  Terrace 16 

Limestone  Valley  and  Upland 13 

Piedmont  Plateau 14 

River  Flood  Plain 11 

SOIL   REGIONS. 

Arid  Southwest 25 

Great  Basin 26 

Great  Plains 17 

Northwest  Intermountain 19 

Pacific  Coast 21 

Rocky  Mountain 23 

Soils.  Province  or  Region. 

Amarillo Great  Plains 18 

Billings Rocky  Mountain 24 

Cahaba River  Flood  Plain 13 

Carrington Glacial  and  Loessial 6 

Carson Great  Basin 28 

Cecil Piedmont  Plateau 15 

Chester Piedmont  Plateau 16 

Clarksville Limestone  Valley  and  Upland 14 

Clyde Glacial  Lake  and  River  .Terrace 17 

Colby Great  Plains 18 

Crawford Great  Plains 18 

Crowley Atlantic  and  Gulf  Coastal  Plain 10 

Dekalb Appalachian  Mountain  and  Plateau 11 

Dunkirk Glacial  Lake  and  River  Terrace 17 

Fargo Glacial  Lake  and  River  Terrace 17 

Fresno Pacific  Coast 22 

Gila Arid  Southwest 26 

Ilagerstown Limestone  Valley  and  Upland 14 

Hanford Pacific  Coast 23 

Houston Atlantic  and  Gulf  Coastal  Plain 10 

Huntington River  Flood  Plain 12 

Imperial Arid  Southwest 26 

Knox , Glacial  and  Loessial 6 

Marshall Glacial  and  Loessial 6 

Mesa Rocky  Mountain 24 

Miami Glacial  and  Loessial 6 

Miller River  Flood  Plain 12 

Morton Great  Plains 18 

3 


4  INDEX. 

Soils.                                                         Province  or  Region.  Page. 

Muck River  Flood  Plain 13 

Norfolk Atlantic  and  Gulf  Coastal  Plain 8 

Orangeburg Atlantic  and  Gulf  Coastal  Plain 9 

Oswego Great  Plains 18 

Peat River  Flood  Plain 13 

Penn Piedmont  Plateau 16 

Placentia Pacific  Coast 22 

Porters Appalachian  Mountain  and  Plateau 11 

Portsmouth Atlantic  and  Gulf  Coastal  Plain 9 

San  Joaquin Pacific  Coast 22 

Sassafras Atlantic  and  Gulf  Coastal  Plain 10 

Stockton Pacific  Coast 23 

Trenton Great  Basin 27 

Vernon Great  Plains 18 

Wabash River  Flood  Plain 12 

Walla  Walla Northwest  Intermountain 20 

Yakima...                           ..Northwest  Intermountain...  20 


IMPORTANT  SOILS  OF  THE  UNITED  STATES. 


The  soils  of  the  United  States  for  purposes  of  classification  are 
grouped  into  seven  soil  provinces,  covering  the  eastern  half  of  the 
United  States,  and  six  soil  regions,  covering  the  western  half.  The 
soil  provinces  differ  in  the  petrographic  and  physical  character  of 
the  rock  from  which  the  soil  material  was  derived,  topography,  ele- 
vation, and  in  processes  by  which  the  soil  material  was  accumulated. 
The  soil  regions  do  not  conform  to  differences  in  the  mode  of  origin 
or  method  of  transportation  of  soil  material,  but  to  great  physio- 
graphic regions,  and  the  soils  within  each  region  differ  in  origin, 
these  differences  being  substantially  the  same  as  the  differences  that 
distinguish  the  different  soil  provinces. 

The  soil  provinces  are  substantially  under  humid  conditions,  and 
the  soil  regions  are  substantially  under  semiarid  or  arid  climatic 
conditions. 

The  total  land  area  covered  by  the  eastern  soil  provinces  amounts 
to  48.5  per  cent,  and  of  the  western  soil  regions  51.5  per  cent  of  the 
United  States.  The  soil  provinces  include  85  per  cent  of  the  rural 
population,  and  the  soil  regions  15  per  cent.  The  soil  provinces 
carry  85  per  cent  of  farm  operators,  with  59  operators  for  every 
10,000  acres  of  total  land  area.  The  western  soil  regions  have  15  per 
cent  of  the  farm  operators,  and  10  operators  per  10,000  acres  of  total 
land  area.  In  the  eastern  soil  provinces  40  per  cent  of  the  area  is 
improved  land  in  farms,  amounting  to  77  per  cent  of  the  improved 
land  in  farms  in  the  United  States.  The  western  soil  regions  have 
11.2  per  cent  of  their  area  as  improved  land  in  farms,  23  per  cent  of 
the  total  improved  land  in  farms  in  the  United  States. 

THE   SOIL  PROVINCES   OF   THE    UNITED    STATES. 

Glacial  and  Loessial  Province. — The  Glacial  and  Loessial  Prov- 
ince covers  an  area  in  which  the  soil  material  has  been  moved  to  its 
present  place  in  part  by  glaciers  and  in  part  by  the  wind  (loess 
deposits).  The  material  is  heterogeneous  in  that  it  contains  frag- 
ments of  crystalline  rocks,  such  as  granite,  gneiss,  and  diabase,  as 
well  as  fragments  of  sedimentary  rocks,  such  as  sandstone,  shale,  and 
limestone,  for  the  most  part  intermingled  but  locally  with  one  or 
more  of  these  classes  of  material  absent. 

5 


6  IMPORTANT   SOILS  OP   THE   UNITED  STATES. 

Soils  of  this  common  origin  occur  north  of  the  Missouri  and  Ohio 
Rivers  with  a  narrow  extension  down  the  Mississippi  to  near  its 
mouth,  and  cover  a  part  of  Pennsylvania  and  nearly  all  of  New 
York  and  the  New  England  States.  North  of  an  irregular  line 
extending  from  Yankton,  S.  Dak.,  to  Cincinnati,  Ohio,  the  surface 
material  is  mainly  glacial  drift,  but  often  locally  modified  by  deposits 
of  rushing  glacial  sheet  waters  and  glacial  rivers.  South  of  this  line 
the  surface  layer  consists  of  stone- free  and  gravel-free  silty  material 
thought  by  many  geologists  to  be  of  loessial  origin,  and  is  underlain 
by  glacial  debris  except  in  the  narrow  southward  extension  along 
the  Mississippi  River. 

West  of  central  Ohio  the  surface  is  in  general  smoother  than  to  the 
east,  and  across  the  southern  part  of  the  area  the  glacial  deposits 
are  thicker,  as  a  rule,  than  are  those  in  the  hilly  .and  mountainous 
country  of  New  York,  Pennsylvania,  eastern  Ohio,  and  New  England. 
In  the  Lake  Region,  however,  the  deposits  over  large  areas  are 
apparently  no  thicker  than  in  central  New  York  and  large  areas  in 
New  England.  The  soils  of  the  supposed  loessial  belt  have  generally 
a  more  uniform  surface,  as  expressed  in  the  term  "  plains." 

The  Glacial  and  Loessial  Province  covers  about  20  per  cent  of  the 
area  of  the  United  States.  It  carries  about  33  per  cent  of  the 
rural  population  of  the  United  States,  with  34.7  per  cent  of  the  farm 
operators,  and  has  about  58  operators  per  10,000  acres  of  total  land 
area.  About  52.9  per  cent  of  the  province  is  improved  land  in  farms, 
and  the  province  carries  42.4  per  cent  of  the  improved  land  in  farms 
in  the  United  States. 

Two  soils,  the  Carrington  silt  loam  and  the  Miami  clay  loam,  have 
been  selected  to  represent  the  general  characteristics  of  the  soils  of 
the  glacial  drift,  and  two  others,  the  Marshall  silt  loam  and  the  Knox 
silt  loam,  to  represent  the  soils  of  loessial  origin.  The  soil  types  com- 
prised in  the  Carrington  series  cover  8.4  per  cent  of  the  province,  the 
soils  of  the  Miami  series  cover  14  per  cent,  those  of  the  Marshall 
series  12.9,  and  of  the  Knox  series  8.4  per  cent.  The  soils  selected  to 
represent  these  series  are  dominant. 

The  Miami  soils  are  similar  in  origin  to  the  Carrington,  both  being 
glacial  deposits,  but  they  differ  in  color,  owing  to  the  high  content  of 
organic  matter  of  the  Carrington,  which  gives  the  soils  of  this  series 
a  very  dark  brown  or  black  color  as  distinguished  from  the  brown 
color  of  the  Miami.  Both  have  a  yellowish-brown  subsoil  and  are 
underlain  by  bowlder  clay  or  other  unweathered  glacial  debris.  The 
Knox  and  Marshall  soils  are  similar  in  origin,  both  being  wind  de- 
posits, but  the  Knox  is  a  brown  soil,  while  the  Marshall  is  very 
dark  brown  to  black,  owing  to  a  much  higher  content  of  organic 
matter.  Both  have  a  3rellowish-brown  subsoil  and  are  generally  un- 
derlain at  depths  of  10  to  20  feet  by  bowlder  clay  or  till.  Organic 


IMPORTANT   SOILS    OF    THE    UNITED   STATES.  7 

content  determines  the  difference  in  color  of  these  soils.  It  is  low  in 
the  glacial  soils  of  the  Miami  series  and  the  wind  deposited  soils  of 
the  Knox  series,  and  they  are  consequently  light  colored,  while  it  is 
high  in  the  ice-deposited  soils  of  the  Carrington  series  and  the  wind- 
deposited  soils  of  the  Marshall  series,  and  accordingly  they  are  dark 
colored.  Both  the  black  series  are  associated  with  original  prairie 
conditions,  an  absence  of  trees  and  a  prevalence  of  grasses,  while 
both  the  light-colored  series  are  associated  with  original  timbered 
conditions. 

The  dark  soils  are  used  in  the  production  of  corn  and  hay,  these 
products  being  sold  or  fed  to  hogs  or  beef  and  dairy  cattle,  under 
the  type  of  agriculture  that  is  found  in  the  corn  belt.  North  of  the 
corn  belt,  however,  where  the  season  is  too  short  for  the  ripening  of 
commercial  crops  of  corn,  these  black  soils,  particularly  the  Carring- 
ton, are  used  for  the  production  of  spring  wheat.  The  Marshall 
soils  are  used  for  the  production  of  corn  to  as  full  an  extent  as  the 
Carrington. 

The  light-colored  soils  are  used  .for  the  production  of  corn,  hay, 
and  winter  wheat. 

The  Carrington  soils  for  the  most  part  lie  within  the  area  in- 
cluded between  a  line  passing  through  central  Kansas,  Nebraska,  and 
the  Dakotas  on  the  west,  through  western  Indiana  on  the  east,  and 
central  Missouri  and  Kansas  on  the  south.  On  the  north  they  extend 
across  the  international  boundary  line  from  North  Dakota  and 
western  Minnesota. 

The  Marshall  soils  occur  in  western  Iowa,  eastern  Nebraska,  north- 
eastern Kansas,  and  in  Missouri  in  belts  on  both  sides  of  the  Missouri 
River,  approximately  parallel  to  but  somewhat  removed  from  that 
stream. 

The  Miami  soils,  in  a  general  way,  lie  east  of  the  Marshall  and 
Carrington  soils.  They  are  associated  with  and  are.  dominant  factors 
in  the  type  of  general  farming  and  dairying  that  prevails  in  the 
western  half  of  Ohio,  central  and  northern  Indiana,  southern  Michi- 
gan, southern  Wisconsin,  and  southeastern  Minnesota. 

The  Knox  soils  in  a  general  way  occur  in  close  association  with  the 
Marshall  soils,  but  extend  farther  south  along  the  Missouri  and 
Mississippi  Rivers.  They  are  dominant  in  the  type  of  farming 
where  winter  wheat  is  a  major  crop,  occurring  in  southwestern  Illi- 
nois, central  Missouri,  the  extreme  northeastern  part  of  Kansas,  and 
the  eastern  part  of  Nebraska. 

Atlantic  and  Gulf  Coastal  Plain  Province.— The.  Atlantic  and 
Gulf  Coastal  Plain  Province  is  a  vast  outwash  plain  and  covers  an 
area  in  which  the  soil  material  has  been  transported  by  rivers  or 
flood  waters  from  one  or  more  of  the  older  soil  provinces,  all  classes 
of  material  being  mixed  according  to  the  length  and  point  of  origin 


8  IMPOBTANT   SOILS  OF   THE   UNITED   SIATES. 

of  the  river  and  its  tributaries  and  the  rate  and  volume  of  the  flow 
from  time  to  time.  The  coarser  sands  and  gravels  have  for  the  most 
part  been  deposited  in  the  river  channel,  while  the  medium  and 
small-sized  grains  of  sand,  silt,  and  clay  have  been  carried  onward 
toward  its  entrance  into  the  ocean.  At  this  point,  or  during  sub- 
sequent submergence  of  the  coast,  the  ocean  waves  have  pounded  and 
agitated  the  material  and  the  ocean  currents  have  operated  to  cause 
a  further  separation  of  the  sands,  fine  sands,  silts,  and  clays,  the 
finer  material  being  carried  into  the  deeper  and  quieter  waters,  and 
the  coarser  material  left  along  the  edge. 

Soils  of  this  common  origin  extend  along  the  coast  from  New 
York  City  to  the  Mexican  border,  and  cover  from  one-third  to  one- 
half  of  all  the  Atlantic  Coast  States,  all  of  Florida,  the  greater  part 
of  Alabama  and  Mississippi,  all  the  uplands  of  Louisiana,  southern 
Arkansas,  southeastern  Oklahoma,  and  what  is  commonly  known  as 
east  Texas  and  south  Texas.  The  soil  material  comprised  in  this 
province  is  estimated  to  cover  about  11.4  per  cent  of  the  United 
States. 

The  Atlantic  and  Gulf  Coastal  Plain  Province  carries  about  19.6 
per  cent  of  the  rural  population  of  the  United  States,  19.9  per  cent 
of  the  farm  operators,  and  has  about  58  operators  per  10,000  acres 
of  total  land  area.  About  27.3  per"  cent  of  the  province  is  improved 
land  in  farms,  which  amounts  to  about  12.5  per  cent  of  the  im- 
proved land  in  farms  in  the  United  States. 

From  the  Potomac  River  northward  the  material  carried  into  the 
sea  came  from  the  glaciated  area  of  New  York  and  northern  Pennsyl- 
vania, from  the  Piedmont,  the  Limestone  Valley,  and  the  Appalachian 
regions,  and  was  transported  by  the  Hudson,  Delaware,  Susque- 
hanna,  and  Potomac  Rivers,  and  a  great  many  smaller  streams.  Be- 
tween the  Potomac  and  the  Roanoke  it  came  from  the  Piedmont,  Ap- 
palachian, and  Limestone  Valley  regions.  From  the  Roanoke  to  the 
Chattahoochee  the  material  came  from  the  crystalline  rocks  of  the 
Piedmont  only  or  from  the  east  slope  of  the  Blue  Ridge,  itself  com- 
posed of  such  rocks.  From  the  Alabama  River- to  southern  Louisi- 
ana the  material  has  been  derived  from  the  rocks  of  the  Mississippi 
basin,  mainly  sedimentary. 

Six  soils  have  been  selected  as  the  dominant  soils  of  this  province. 
The  Norfolk  soils  cover  about  32.7  per  cent,  the  Orangeburg  soils 
about  12  per  cent,  the  Portsmouth  soils  about  6.2  per  cent,  the  Hous- 
ton soils  about  6.2  per  cent,  the  Sassafras  soils  about  3.7  per  cent, 
and  the  Crowley  soils  about  1.1  per  cent  of  the  province.  The  types 
selected  are  the  dominant  types  of  each  of  these  series. 

The  Norfolk  soils  are  gray,  with  yellow  subsoils.  They  are  de- 
veloped principally  in  that  part  of  the  Coastal  Plain  lying  between 
the  Potomac  and  Alabama  Rivers,  with  a  moderate  development  in 


IMPORTANT  SOILS   OF   THE   UNITED   STATES.  9 

northeastern  Texas.  They  are  identified  with  a  variety  of  agricul- 
tural interests,  depending  upon  the  texture  of  the  soils  and  upon 
climatic  conditions.  The  Norfolk  fine  sandy  loam,  represented  in 
the  accompanying  collection  of  samples,  is  considered  the  dominant 
soil  of  the  series,  having  a  greater  extent  and  a  wider  range  of 
agricultural  adaptation  than  any  of  the  other  types.  It  is  one  of  the 
most  important  cotton  soils  of  the  South,  it  is  the  dominant  corn  soil 
of  the  Norfolk  series,  and  is  an  important  soil  for  the  production  of 
truck  crops  where  yield  rather  than  earliness  of  production  is  consid- 
ered. In  southern  Virginia  and  North  and  South  Carolina  the  deeper 
phases  of  this  type  are  important  in  the  production  of  bright  tobacco. 
In  southwestern  Georgia  and  western  Florida  the  fine  sandy  loam  is 
the  leading  cigar-wrapper  tobacco  soil.  This  is  the  most  extensively 
used  soil  for  market  peanuts,  the  industry  centering  in  southeastern 
Virginia  and  northeastern  North  Carolina.  Farther  south  it  produces 
a  cane  sirup  of  good  yield  and  bright  color.  The  Norfolk  sand  and 
fine  sand  mature  truck  crops  earlier  and  have  this  advantage  over 
the  fine  sandy  loam  as  special-purpose  soils  under  intensive  systems 
of  agriculture.  The  Norfolk  sand  is  peculiarly  associated  with  the 
production  of  citrus  fruit  in  Florida  and  of  watermelons  in  Georgia, 
but  both  of  these  types  are  less  well  adapted  to  the  staple  farm  crops 
than  is  the  fine  sandy  loam.  The  Norfolk  sandy  loam  is  associated 
with  about  the  same  agricultural  interests  as  the  fine  sandy  loam,  but 
because  of  its  somewhat  coarser  texture  has  not  quite  the  productive 
capacity  of  that  type. 

The  Orangeburg  soils  are  gray,  with  red  subsoils.  They  occur  in 
that  portion  of  the  Coastal  Plain  between  South  Carolina  and  the 
Alabama  River  and  are  quite  extensively  developed  in  eastern 
Mississippi,  northern  Louisiana,  and  in  eastern  Texas.  In  South 
Carolina  and  northern  Georgia  they  occur  generally  west  of  the 
Norfolk  belt,  while  in  southern  Georgia,  Alabama,  and  Mississippi 
they  flank  the  Norfolk  belt  on  each  side,  extending  down  into 
western  Florida.  Type  for  type  they  are  adapted  to  about  the 
same  range  of  agricultural  use  as  the  Norfolk  soils,  but  are  some- 
what stronger  and  stand  up  better  under  average  conditions  of 
cultivation  and  use.  They  are  peculiarly  associated  with  the  pro- 
duction of  peaches  in  central  Georgia  and  east  Texas.  In  addition, 
in  southwestern  Georgia  and  western  Florida  they  are  associated 
with  the  production  of  cigar-wrapper  tobacco,  giving  heavier  yields 
but  a  leaf  not  so  desirable  in  texture  as  that  grown  on  the  corre- 
sponding .  Norfolk  types. 

The  Portsmouth  soils  are  black,  with  light-gray  or  mottled  yellow 

and  gray  subsoils,  often  with  a  wet,  compact  brown  sand  substratum 

that  has  the  effect  of  a  hardpan.     These  soils  are  found  largely 

throughout  the  eastern  part  of  the  Coastal  Plain  from  New  York 

60365—16 -2 


10  IMPORTANT   SOILS  OF   THE   UNITED  STATES. 

City  to  Florida  and  throughout  that  State,  occurring  near  the  coast 
line  or  bordering  the  larger  rivers  or  swamps.  They  generally  need 
drainage  for  their  highest  development.  They  are  rich  in  organic 
matter,  and  are  associated  with  the  production  of  corn,  cabbage,  and 
onions,  and  are  peculiarly  adapted  to  certain  varieties  of  straw- 
berries. 

The  Houston  soils  are  dark-brown  to  black,  with  yellowish-brown 
to  grayish  subsoils.  Unlike  the  other  soils  of  the  Coastal  Plain, 
they  are  derived  largely  from  marine  calcareous  sediments,  the  sub- 
soil particularly  being  very  calcareous.  They  occur  in  what  is  com- 
monly known  as  the  "black-prairie  belt,"  extending  from  eastern 
Alabama  through  that  State  into  northeastern  Mississippi  and  in  the 
"black  waxy  belt"  of  central  Texas.  These  soils  are  excellent  for 
growing  cotton.  They  are  also  peculiarly  adapted  to  the  production 
of  corn  and  forage  crops  and  to  alfalfa,  and  are  therefore  well  suited 
to  the  raising  and  feeding  of  hogs  and  cattle. 

The  Sassafras  soils  are  light  brown,  with  reddish-yellow  subsoils. 
They  are  found  only  in  that  part  of  the  Coastal  Plain  between  New 
York  City  and  the  Potomac  River.  They  are  associated  with  the 
type  of  agriculture  that  has  long  been  prevalent  in  central  and 
southern  New  Jersey,  in  Delaware,  and  on  the  eastern  shores  of 
Maryland,  where  wheat  is  a  dominant  crop,  associated  with  corn 
and  hay  grasses,  and  where  the  feeding  of  cattle  and  the  dairy  inter- 
ests have  been  of  great  importance.  These  soils  have  been  dominant 
in  the  production  of  peaches  and  of  vegetables  for  canning.  In  their 
adaptation  to  this  form  of  general  agriculture  they  are  more  like  the 
Hagerstown  soils  of  the  Limestone  Valley,  the  Chester  soils  of  the 
Piedmont,  and  the  Miami  soils  of  the  Glacial  and  Loessial  Province 
than  any  other  soils  of  the  Coastal  Plain. 

The  Crowley  soils  are  gray,  with  mottled  gray,  yellow,  and  red 
subsoils.  They  occur  only  in  that  part  of  the  Coastal  Plain  which  has 
received  material  through  the  Mississippi  drainage.  They  are  pecul- 
iarly associated  with  the  production  of  rice  in  southern  Louisiana. 

Appalachian  Mountain  and  Plateau  Province. — The  Appalachian 
Mountain  and  Plateau  Province  covers  an  area  in  which  the  soil 
material  has  mainly  been  transported  presumably  by  rivers  no  longer 
in  existence,  the  material  having  subsequently  been  acted  upon  by 
ocean  waves  and  currents,  by  which  it  was  assorted  into  sands 
and  clays  during  repeated  submergences  and  later  consolidated  into 
sandstone  and  shale  rocks.  Since  the  final  submergence  the  material 
has  been  pushed  up  to  the  relatively  high  altitude  of  the  Appalachian 
Mountain  Range  and  the  high  plateau  to  the  west. 

Soils  of  this  common  origin  cover  central  and  southwestern  Penn- 
sylvania, western  Maryland,  southeastern  Ohio,  most  of  West  Vir- 


IMPORTANT   SOILS   OF   THE   UNITED   STATES.  11 

ginia,  and  a  small  part  of  Virginia,  South  Carolina,  North  Carolina, 
Georgia,  and  Alabama,  eastern  Kentucky,  and  northern  Arkansas, 
with  small  areas  in  southern  Indiana  and  western  Kentucky.  This 
material  covers  about  4.5  per  cent  of  the  United  States. 

The  Appalachian  Mountain  and  Plateau  Province  carries  about  11.4 
per  cent  of  the  rural  population  of  the  United  States  and  9.3  per  cent 
of  the  farm  operators,  giving  70  operators  per  10,000  acres  of  total 
land  area.  About  34.7  per  cent  of  the  province  is  improved  land  in 
farms.  This  amounts  to  6.2  per  cent  of  the  improved  land  in  farms 
in  the  United  States. 

Two  soils  have  been  selected  to  represent  this  province,  one  from 
the  Porters  series  which  covers  9.6  per  cent  of  the  province,  and  the 
other  from  Dekalb  series  which  covers  44  per  cent. 

The  Porters  series  includes  types  with  dark-red  surface  soils  and 
red  subsoils.  They  are  derived  from  the  crystalline  rocks  of  the 
Blue  Ridge  Mountains  and  of  the  Ozark  Mountains.  On  account  of 
their  generally  steep  and  often  rough  topography  they  are  very  little 
used  for  agriculture,  though  producing  excellent  fruit,  especially 
apples,  at  suitable  elevations  and  with  proper  exposure.  They  are 
used  also  as  cheap  mountain  pasture  for  the  raising  of  young  cattle. 

The  Dekalb  soils  are  yellowish  gray  on  the  surface  with  a  light- 
yellow  subsoil.  They  are  derived  from  the  disintegration  of  sand- 
stone and  shale.  Owing  partly  to  their  isolated  position,  partly  to 
their  rough  topography,  and  partly  to  the  character  of  the  soil 
material  they  are  not  highly  developed  for  agriculture.  Locally 
they  are  of  importance  for  the  production  of  fruit,  especially  late 
varieties  of  peaches.  They  produce  a  considerable  proportion  of  the 
commercial  crops  of  buckwheat  and  rye.  They  furnish  cheap  pasture 
for  young  cattle  and  locally  for  sheep.  Very  little  corn  and  wheat 
is  produced  on  them.  The  principal  agriculture  in  the  region  is 
carried  on  in  the  valleys  either  on  soils  derived  from  limestone  or  on 
soils  belonging  in  the  River  Flood  Plain  Province. 

Rii'er  Flood  Plain  Province. — The  River  Flood  Plain  Province 
comprises  an  area  in  which  the  soil  material  has  been  and  is  being 
transported  and  laid  down  by  running  water  mainly  during  floods. 
There  is  more  or  less  intermingling  of  material  during  its  transport, 
and  there  is  a  certain  amount  of  segregation  of  material  according  to 
size,  the  coarser  sand  and  gravel  being  deposited  in  or  near  the  chan- 
nel of  the  stream,  the  sandy  loams,  loams,  and  silt  loams  being  spread 
out  on  its  flood  plains,  and  the  finest  clay  segregated  in  swampy  areas 
where  the  water  is  stagnant  or  flowing  with  low  velocity.  The 
River  Flood  Plain  extends  throughout  all  the  soil  provinces,  the 
river  channels  reaching  like  fingers  into  the  uplands.  The  river 
itself  is  far  more  extensive  than  the  visible  stream,  extending,  as  it 
does,  in  the  form  of  ground  water  at  a  moderate  depth  below  the 


12  IMPORTANT   SOILS  OF    THE   UNITED  STATES. 

surface  throughout  its  drainage  basin,  the  movement  being  extremely 
slow.  Between  the  ground  water  and  the  surface  the  solvent  action 
of  meteoric  wraters  on  the  soil  material  and  the  removal  of  dissolved 
mineral  matter  is  quite  important.  During  periods  of  heavy  rains 
the  sheet  water  covering  the  surface  of  the  uplands  is  a  visible  ex- 
tension of  the  river,  and  this  acts  in  the  transportation  of  material 
to  the  extent  of  excessive  erosion  at  times  in  some  places.  Soils 
of  the  River  Flood  Plains  Province  occupy  the  flood  plains  and 
terraces  along  existing  rivers  and  cover  about  4  per  cent  of  the  area 
of  the  United  States. 

Owing  to  the  manner  of  occurrence  of  the  soils  of  this  province, 
which  are  developed  in  narrow  strips  extending  throughout  the  other 
soil  provinces,  they  are  farmed  mainly  in  connection  with  the  soils 
of  the  associated  provinces,  and  no  estimate  of  the  rural  population, 
farm  operators,  or  improved  land  in  farms  can  be  given  for  this 
province  separately. 

Four  soils  have  been  selected  to  represent  this  province.  Three  of 
these,  the  Wabash,  covering  approximately  10.6  per  cent  of  the 
province,  the  Huntington,  covering  about  6.2  per  cent,  and  the  Miller 
3.1  per  cent,  are  first-bottom  soils,  and  one,  the  Cahaba,  is  a  terrace 
soil,  covering  about  3.2  per  cent  of  the  province.  TWTO  classes  of 
miscellaneous  material,  Muck  and  Peat,  are  also  represented,  the 
former  covering  approximately  4.6  per  cent  and  the  latter  about  1.8 
per  cent  of  the  province. 

The  Wabash  soils  are  black  with  gray  subsoils.  They  occur 
throughout  the  Glacial  and  Loessial  Province,  north  of  the  Ohio 
River.  They  are  first-bottom  soils  and  generally  in  need  of  drainage. 
Where  properly  drained  they  are  peculiarly  adapted  to  corn  and  this 
is  the  chief  crop,  with  the  hay  grasses  as  the  next  most  important 
product. 

The  Huntington  soils  are  brown  with  lighter  brown  subsoils. 
They  occur  throughout  the  Appalachian  Mountain  and  Plateau  and 
the  Limestone  Valley  and  Upland  Provinces.  They  are  first-bottom 
soils  subject  to  overflow,  and  are  generally  in  need  of  drainage. 
When  properly  drained  and  protected  from  overflow  they  are  domi- 
nant in  the  agriculture  of  the  region,  particularly  in  the  Appalachian 
Province.  They  are  peculiarly  adapted  to  corn  and  hay  grasses. 

The  Miller  soils  are  chocolate-red  with  chocolate-red  subsoils. 
These  soils  are  calcareous.  They  are  first-bottom  soils,  although 
large  areas  are  not  subject  to  overflow.  The  material  has  been 
derived  mainly,  or  to  a  considerable  extent,  from  the  Permian  Red 
Beds  of  the  residual  prairie  region  and  the  soils  are  importantly 
developed  along  the  Arkansas.  Red,  and  Brazos  Rivers  in  Texas  and 
Louisiana.  They  are  peculiarly  adapted  to  cotton,  corn,  and  alfalfa. 


IMPORTANT   SOILS   OF    THE   UNITED   STATES.  13 

The  Cahaba  soils  are  brown  with  reddish-brown  subsoils.  They 
occur  in  the  Coastal  Plain  Province,  chiefly  from  South  Carolina  to 
central  Mississippi.  They  consist  mainly  of  Coastal  Plain  material 
with  some  Piedmont  material.  They  are  peculiarly  adapted  to 
cotton,  and  this  is  the  dominant  crop  produced. 

Muck  is  black  and  consists  largely  of  vegetable  matter  which  has 
accumulated  through  the  growth  and  decay  of  rank  vegetation  under 
conditions  of  poor  drainage.  The  amount  of  true  soil  material 
varies,  the  amount  of  organic  matter  ranging  from  about  20  per  cent 
to  50  per  cent  or  even  as  high  as  85  per  cent.  The  organic  matter 
below  the  immediate  surface  generally  has  broken  down,  showing 
little  or  no  fiber.  The  value  of  the  Muck  for  agriculture  varies 
widely  wTith  the  character  of  the  vegetation  from  which  it  is  derived. 
Productive  areas  of  Muck,  where  properly  drained,  are  quite  valu- 
able, particularly  for  the  growing  of  the  heavier  vegetables,  such  as 
cabbage,  onions,  and  celery. 

Peat  is  usually  brown  and  fibrous,  but  sometimes  occurs  as  black, 
nonfibrous  material.  The  characteristic  which  distinguishes  it  from 
Muck  is  the  small  amount  of  mineral  matter  present,  Peat  being 
nearly  a  pure  deposit  of  vegetable  matter,  the  organic  content  rang- 
ing from  85  per  cent  to  93  per  cent.  The  brown  fibrous  peat,  unless  it 
can  be  partially  burned  over  and  covered  with  the  underlying  sand, 
has  proved  to  be  one  of  the  most  difficult  soil  materials  to  grow  com- 
mercial crops  upon.  The  black  nonfibrous  peat  approaches  more 
nearly  the  agricultural  value  of  muck. 

Limestone  Valley  and  Upland  Province. — The  Limestone  Valley 
and  Upland  Province  covers  an  area  in  which  the  soil  material  has 
been  derived  from  limestone  rocks,  which  were  laid  down  under  the 
ocean  and  contain  slight  admixtures  of  soil  materials  as  impurities. 
With  the  gradual  solution  of  the  lime  carbonate,  these  impurities 
have  been  left  as  the  present  soil  material  of  the  province. 

Soils  of  this  common  origin  occur  mainly  in  a  rather  narrow  valley 
lying  between  the  Blue  Ridge  on  the  east  and  the  Appalachian 
Mountains  on  the  west  and  extending  from  eastern  Pennsylvania  to 
central  Alabama,  in  the  Central  Basin  of  Tennessee  and  the  Bluegrass 
Region  of  Kentucky  and  the  contiguous  highland  region,  over  the 
greater  part  of  Missouri  south  of  the  Missouri  River,  and  in  northern 
Arkansas.  This  province  is  estimated  to  cover  3.5  per  cent  of  the 
United  States. 

The  Limestone  Valley  and  Upland  Province  carries  approximately 
8.6  per  cent  of  the  rural  population  of  the  United  States,  and  9  per 
cent  of  the  farm  operators,  with  83  operators  per  10,000  acres  of  total 
land  area,  and  has  4-5.4  per  cent  of  its  area  classed  as  improved  land 
in  farms,  which  is  about  6.4  per  cent  of  the  total  improved  land  in 
farms  in  the  United  States. 


14  IMPORTANT  SOILS  OF   THE  UNITED  STATES. 

Two  series  have  been  selected  as  the  dominant  soils  of  this  prov- 
ince— the  Clarksville  series,  which  covers  about  55  per  cent  of  the 
province,  and  the  Hagerstown  series,  which  covers  about  28  per  cent. 
The  types  selected  are  the  dominant  soils  of  these  series. 

The  Clarksville  soils  are  light  gray,  with  yellow  subsoils.  They 
are  developed  principally  in  the  southern  part  of  the  Great  Valley, 
on  the  "  Highland  Rim  "  about  the  Central  Basin  and  Bluegrass  Re- 
gion, and  in  the  Missouri  and  Arkansas  area,  and  constitute  the 
upland  limestone  areas,  as  distinguished  from  the  valleys  occupied 
by  the  Hagerstown  soils.  A  difference  in  topography  is  due  to  the 
more  resistant  nature  of  the  limestone,  which  is  frequently  siliceous 
and  includes  interbedded  chert  rock,  giving  rise  to  the  Clarksville,  as 
compared  with  the  purer  limestone,  giving  rise  to  the  Hagerstown 
soils.  The  Clarksville  soils  have  an  important  place  in  the  produc- 
tion of  dark  tobacco  in  Kentucky  and  Tennessee  and  locally  in  the 
production  of  strawberries,  cantaloupes,  and  peaches.  In  Alabama 
and  Georgia  they  are  used  for  cotton  and  in  the  northern  areas  to 
some  extent  for  general  agriculture,  with  light  yields  of  corn,  wheat, 
and  hay,  large  areas  being  still  undeveloped  or  used  for  cheap  pasture 
for  the  raising  of  cattle. 

The  Hagerstown  soils  are  brown,  with  reddish-brown  subsoils. 
They  occur  in  the  northern  part  of  the  Great  Valley  and  in  the  Cen- 
tral Basin  of  Tennessee  and  the  Bluegrass  Region  of  Kentucky. 
They  are  dominant  in  the  type  of  general  farming  which  prevails  in 
the  Lancaster  Valley  of  Pennsylvania,  in  the  Frederick  Valley  of 
Maryland,  in  the  Shenandoah  Valley  of  Virginia,  and  in  the  Central 
Basin  and  Bluegrass  Region,  where  wheat,  corn,  pasture  grasses,  par- 
ticularly bluegrass,  are  important,  and  the  fattening  of  cattle,  the 
raising  of  horses,  and  the  dairy  industry  are  the  principal  animal 
industries.  In  Pennsylvania  they  are  dominant  in  the  production  of 
cigar-filler  tobacco  and  in  central  and  northern  Kentucky  in  the 
production  of  white  Burley  tobacco. 

Piedmont  Plateau  Province. — The  Piedmont  Plateau  Province  cov- 
ers an  area  in  which  the  soil  material  has  been  derived  from  the  dis- 
integration in  place  of  igneous  and  usually  strongly  crystalline  rock 
such  as  granite,  from  highly  metamorphosed  rocks  such  as  gneiss, 
from  rather  slightly  metamorphosed  rocks  such  as  phyllites,  and  to 
a  small  extent  from  slightly  or  not  at  all  metamorphosed  rocks  such 
as  Triassic  sandstone  and  shale. 

Soils  of  this  common  origin  lie  in  a  belt  between  the  Atlantic  Coastal 
Plain  and  the  Appalachian  Mountains  and  Plateaus,  extending  from 
northern  New  Jersey  to  central  Alabama,  and  averaging  from 
25  to  50  miles  in  width  from  its  northern  limits  to  central  Virginia 
find  about  100  miles  in  width  southward.  The  soil  material  of  this 
origin  covers  about  2.5  per  cent  of  the  area  of  the  United  States. 


IMPORTANT  SOILS   OF   THE   UNITED   STATES.  15 

The  Piedmont  Plateau  Province  carries  about  8  per  cent  of  the 
rural  population  of  the  United  States  and  about  7.9  per  cent  of  the 
farm  operators,  giving  107  operators  per  10,000  acres  of  total  land 
area,  with  45.1  per  cent  of  the  province  classed  as  improved  land  in 
farms,  which  is  about  4.4  per  cent  of  the  improved  land  in  farms  in 
the  United  States. 

Three  series  have  been  selected  as  the  dominant  soils  of  this 
province,  the  Cecil  series,  covering  about  60  per  cent,  the  Chester 
series,  about  6  per  cent,  and  the  Penn  series,  about  5.5  per  cent  of 
the  province.  The  soil  types  selected  to  represent  these  series  are 
dominant. 

The  Cecil  clay  is  red,  with  a  red  subsoil.  The  Cecil  sandy  loam 
is  gray,  with  a  red  subsoil.  Both  are  derived  typically  from  granite. 
Locally,  however,  others  of  the  highly  crystalline  or  metamorphic 
rocks  have  contributed  to  their  formation.  The  difference  in  texture 
and  in  color  of  the  surface  soils  of  the  Cecil  sandy  loam  and  the 
Cecil  clay  is  probably  due  to  incipient  erosion.  In  the  level  areas 
or  where  the  slope  is  very  gentle,  the  agitation  of  the  raindrops  and 
the  action  of  slow-flowing  sheet  water  have  removed  the  finer 
material  from  the  surface,  and  left  a  preponderance  of  coarser  sands, 
forming  the  sandy  loam  cover  of  the  Cecil  sandy  loam  type.  On  the 
steeper  slopes  or  where  the  influence  of  the  sheet  water  resulting 
from  heavy  rains  has  been  sufficiently  active  to  remove  the  coarser 
grains  of  sand  with  the  finer  material,  usually  no  such  marked  sepa- 
ration has  resulted,  and  the  heavier  members  of  the  Cecil  series  have 
a  red  soil  as  well  as  a  red  subsoil. 

The  Cecil  sandy  loam  is  identified  with  that  form  of  agriculture 
prevalent  in  the  central  portion  of  North  Carolina,  the  western  por- 
tion of  South  Carolina,  northern  Georgia,  and  central  Alabama, 
where  cotton  is  the  dominant  crop,  with  corn  grown  mainly  for  home 
use.  Locally  there  is  some  production  of  peaches,  watermelons,  and 
truck  crops,  and  in  North  Carolina  of  dark  tobacco.  The  Cecil  clay, 
extending  from  central  Virginia  southward,  is  one  of  the  important 
cotton  soils  from  North  Carolina  southward.  In  southern  Virginia  it 
is  dominant  in  the  production  of  the  Virginia  type  of  export  tobacco 
leaf,  and  in  North  Carolina  in  the  production  of  domestic  manufac- 
turing tobacco.  It  is  a  much  more  difficult  soil  to  work  than  is  the 
Cecil  sandy  loam,  and  its  full  value  has  not  been  developed  with  the 
light  equipment  of  horses  and  implements  that  is  generally  used. 
Its  true  place  is  for  the  production  of  corn,  small  grains,  and  forage 
crops,  tobacco,  and  for  the  fattening  of  cattle  and  dairying,  as  modi- 
fied by  the  range  of  climatic  conditions  under  which  the  soil  occurs 
and  by  market  and  transportation  facilities.  It  is  an  excellent  soil 
for  hay  grasses  rather  than  for  pasture  grasses. 


16  IMPORTANT   SOILS  OF   THE   UNITED   STATES. 

The  Chester  soils  are  gray,  with  yellow  subsoils.  They  occur  from 
northern  Virginia  northward.  They  are  derived  typically  from 
gneiss,  although  the  more  highly  crystalline  rocks  and  the  less  meta- 
morphosed rocks  have  contributed  locally  to  their  formation.  These 
soils  are  dominant  in  that  type  of  agriculture  which  is  characteristic 
of  northern  Virginia,  central  Maryland,  and  southeastern  Pennsyl- 
vania, in  which  general  farming  is  practiced,  with  corn,  wheat,  and 
both  pasture  and  hay  grasses  as  dominant  factors,  and  with  the  feed- 
ing of  cattle,  the  dairy  interests,  and,  locally,  the  production  of  can- 
ning crops,  particularly  sweet  corn  and  tomatoes,  as  other  important 
industries. 

The  Penn  soils  are  Indian-red  in  color,  and  have  Indian-red  sub- 
soils. They  occur  in  a  rather  narrow  and  discontinuous  belt  extend- 
ing through  the  center  of  the  Piedmont  region  from  North  Carolina 
northward.  They  are  derived  from  the  disintegration  of  Triassic 
sandstone  and  shale,  but  little,  if  at  all,  metamorphosed.  They  are 
associated  with  the  same  type  of  agriculture  as  prevails  on  the  Ches- 
ter soils  and  have  about  the  same  adaptation  as  the  Hagerstown  soils, 
but  are  not  quite  so  productive  as  either  of  these  series,  and  are  more 
influenced  by  unfavorable  climatic  conditions  in  unusually  wet  or 
dry  periods. 

Glacial  Lake  and  River  Terrace  Province. — The  Glacial  Lake  and 
River  Terrace  Province  covers  an  area  in  which  the  soil  material  has 
been  derived  from  glacial  material,  reworked,  carried  by  glacial  rivers, 
and  deposited  as  terraces,  or,  after  having  been  delivered  by  the 
rivers  and  discharged  into  the  glacial  lakes,  has  been  reworked  by 
wave  action  and  redistributed  by  the  lake  currents  and  then  left  in 
relatively  depressed  areas  by  the  recession  or  disappearance  of  the 
lake. 

Soils  of  this  common  origin  occur  generally  bordering  the  Great 
Lakes,  with  narrow  strips  along  some  of  the  Newr  York  and  New 
England  rivers,  along  the  Red  River  of  the  North,  on  the  site  of  the 
old  glacial  lake  Agassiz,  and  in  numerous  small  areas  throughout  the 
glacial  regions,  where  former  glacial  lakes  existed  but  have  entirely 
disappeared.  Soil  materials  of  this  origin  cover  about  2.3  per  cent 
of  the  area  of  the  United  States. 

The  Glacial  Lake  and  River  Terrace  Province  carries  about  4.4 
per  cent  of  the  rural  population  of  the  United  States  and  4.2  per  cent 
of  the  farm  operators,  giving  about  63  operators  per  10.000  acres  of 
total  land  area,  with  56.6  per  cent  of  the  province  classed  as  improved 
land  in  farms,  which  is  about  5.1  per  cent  of  the  improved  land  in 
farms  in  the  United  States. 

Three  soils  have  been  selected  as  the  dominant  soils  of  the  province, 
the  Clyde  series,  covering  about  17  per  cent,  the  Dunkirk  series, 


IMPORTANT   SOILS   OF    THE    UNITED   STATES.  17 

covering  about  16  per  cent,  and  the  Fargo  series,  covering  about 
18  per  cent  of  the  province.  The  types  selected  to  represent  these 
series  are  dominant. 

The  Clyde  soils  are  black,  with  drab  subsoils.  They  occur  east  of 
Minnesota.  In  many  places  they  are  in  need  of  drainage.  They  are 
dominant  in  the  production  of  sugar  beets,  especially  in  Michigan 
and  Wisconsin,  in  the  production  of  cabbage  and  onions,  and  locally 
in  the  production  of  corn  and  hay  grasses. 

The  Dunkirk  soils  are  light  brown,  with  yellow  subsoils.  Their 
greatest  development  is  in  New  York  State  along  the  shores  of 
Lake  Erie  and  Lake  Ontario.  They  have  much  better  natural 
drainage  than  have  the  Clyde  soils.  These  soils  are  dominant  in  the 
production  of  fruit,  especially  apples,  in  the  production  of  table 
grapes,  corn,  and  hay  grasses,  in  the  feeding  of  cattle,  and  in  the 
dairy  industry. 

The  Fargo  soils  are  black,  with  drab  to  gray  subsoils,  the  material 
usually  being  highly  calcareous.  They  are  confined  to  Minnesota, 
the  Dakotas,  and  Iowa. 

THE  SOIL  REGIONS  OF  THE  UNITED  STATES. 

Great  Plains  Region. — The  Great  Plains  is  a  vast  outwash  plain, 
and  consists  of  heterogeneous  material  which  was  transported,  segre- 
gated, and  arranged  under  river  and  marine  conditions,  and  later 
more  or  less  consolidated  into  sandstone,  shale,  and  limestone,  and 
elevated  above  the  level  of  the  ocean. 

Subsequently  a  large  part  of  the  surface  has  been  covered  by 
alluvial-fan  material  and  river-borne  material  from  the  Rocky  Moun- 
tains, and  a  considerable  part  r:y  wind  deposits  of  silt  and  sand. 
The  Great  Plains  Region  has  an  elevation  of  about  8,000  feet  near 
the  Rocky  Mountains,  and  slopes  gently  eastward  to  an  elevation  of 
about  800  feet  along  the  Mississippi  River. 

This  region  comprises  western  North  Dakota,  southeastern  Mon- 
tana, the  western  and  greater  portions  of  South  Dakota,  Nebraska, 
and  Kansas,  the  eastern  portions  of  Wyoming,  Colorado,  and  New 
Mexico,  and  northwestern  Texas,  and  extends  a  short  distance  into 
western  Missouri.  The  region  covers  about  17.4  per  cent  of  the  total 
area  of  the  United  States. 

The  Great  Plains  Region  carries  about  8.7  per  cent  of  the  rural 
population  of  the  United  States,  and  10.-2  per  cent  of  the  farm 
operators,  having  about  10  operators  per  10.000  acres  of  total  land 
area.  About  '23.4  per  cent  of  the  region  is  improved  land  in  farms, 
which  amounts  to  about '16.3  per  cent  of  the  improved  land  in  farms 
in  the  United  States. 


18  IMPORTANT   SOILS   OF   THE   UNITED   STATES. 

Six  soils  have  been  selected  as  the  dominant  soils  of  the  Great 
Plains  Region.  The  Crawford  silt  loam,  the  Oswego  silt  loam,  the 
Morton  fine  sandy  loam,  and  the  Vernon  silt  loam  represent  residual 
soils  weathered  from  the  consolidated  rocks.  The  Amarillo  silty 
clay  loam  represents  the  alluvial-fan  material,  and  the  Colby  silt 
lo'am  the  wind-laid  material. 

The  Crawford  soils  cover  about  5.1  per  cent  of  the  area  thus  far 
surveyed  in  this  region,  the  Oswego  soils  about  1  per  cent,  the 
Morton  soils  about  9.6  per  cent,  the  Vernon  soils  about  1.8  per  cent, 
the  Amarillo  soils  about  8.3  per  cent,  and  the  Colby  soils  about  12.1 
per  cent.  The  types  selected  are  the  dominant  types  of  these  series. 

The  Crawford  soils  have  dark-brown  to  reddish-brown  surface 
soils  and  reddish-brown  to  red  subsoils.  These  are  residual  lime- 
stone soils  of  the  prairie  region.  Limestone  is  frequently  encountered 
2  to  5  feet  below  the  surface,  but  the  soil  itself  contains  only  a  small 
percentage  of  lime.  These  are  important  general-farming  and  fruit- 
growing soils  of  Iowa,  Kansas,  Missouri,  and  Texas. 

The  Oswego  soils  are  gray  to  yellowish  brown,  with  yellow  to 
drab,  stiff,  impervious  subsoils.  They  occupy  level  to  gently  rolling 
prairies.  These  soils  are  derived  from  shale.  They  are  less  pro- 
ductive than  the  Crawford  soils,  but  are  important  in  the  produc- 
tion of  general  farm  crops  in  Kansas,  Missouri,  and  Oklahoma. 

The  Morton  soils  are  brown,  with  light-brown  or  gray  subsoils. 
They  have  a  high  lime  content.  The  surface  of  these  soils  is  undu- 
lating to  rolling,  and  drainage  is  good.  The  Morton  soils  are  de- 
rived mainly  from  fine-grained  sandstones  and  shales.  These  are 
important  wheat  soils  of  the  Dakotas  and  the  eastern  parts  of  Mon- 
tana and  Wyoming. 

The  Vernon  soils  have  reddish-brown  surface  soils  and  light  red- 
dish brown,  compact  subsoils.  They  are  derived  mainly  from  the 
sandstones  and  shales  of  the  Permian  Red  Beds,  and  contain  large 
quantities  of  lime  and  gypsum.  These  are  the  productive  red  soils 
so  extensively  developed  in  Kansas,  Oklahoma,  and  western  Texas. 
They  are  peculiarly  adapted  to  wheat,  corn,  cotton,  and  forage 
crops,  particularly  kafir,  and  to  alfalfa  where  moisture  conditions 
are  favorable. 

The  Amarillo  soils  are  brown  to  reddish  brown,  and  are  under- 
lain by  reddish-brown  subsoils.  They  occupy  the  high  plateau  of 
Kansas,  Oklahoma,  and  Texas,  and  are  derived  from  unconsolidated 
alluvial-fan  materials.  They  are  the  dominant  kafir  and  small-grain 
soils  of  the  region  in  which  they  occur. 

The  surface  soils  of  the  Colby  series  are  gray  to  brownish  gray, 
with  brown  silt  loam  subsoils.  The  topography  varies  from  almost 
flat  to  rolling.  These  soils  are  derived  by  weathering  from  wind- 


IMPORTANT  SOILS   OF   THE   UNITED  STATES.  19 

blown  materials.  They  are  important  in  the  production  of  wheat, 
corn,  and  forage  crops  in  northwestern  Kansas  and  southwestern 
Nebraska,  and  in  eastern  Colorado.  These  are  the  dominant  wheat 
soils  of  western  Kansas. 

Northwest  Intermountain  Region. — The  Northwest  Intermountain 
Region  covers  an  area  in  which  the  soil  material  is  mainly  under- 
lain by  sheets  or  flows  of  basaltic  rocks  of  comparatively  recent  date. 

In  the  gravels  of  the  region  basaltic  material  is  dominant.  Owing, 
however,  to  a  variety  of  dynamic  agencies  subsequently  active  in 
the  formation  and  modification  of  the  soil  material,  much  of  the 
original  basaltic  surface  has  been  veneered  with  transported  and 
unconsolidated  material  derived  from  a  variety  of  rocks.  In  cer- 
tain localities  the  underlying  rocks  have  been  faulted  and  uplifted 
or  folded  by  movements  of  the  earth's  crust,  and  in  other  cases  vol- 
canic cones  and  masses  rise  above  the  general  level.  In  such  localities 
residual  soils  derived  through  weathering  from  the  basaltic  rock  in 
place  occur.  They  are  usually  shallow,  stony,  of  rough  topography, 
and  nonirrigable.  In  other  cases  the  soil  material  is  composed  largely 
of  pumice  or  other  fine  fragmental  material  ejected  from  volcanic 
cones  or  craters  now  extinct. 

Of  the  transported  material,  extensive  areas  of  the  desert  plains, 
which  make  up  most  of  the  present  surface,  consist  of  old  deposits  of 
streams  now  extinct  but  once  flowing  in  conspicuous  valleys,  by 
which  their  courses  may  be  traced.  They  indicate  a  former  period  of 
less  arid  conditions  than  now  prevail,  and  much  of  the  waters  and 
sediments  were  derived  from  melting  glacial  ice.  In  the  northern 
part  of  the  region  extensive  glacial  outwash  plains  of  this  character 
occur.  Other  portions  of  the  region  were  subject  to  deposition  of 
light-colored  sediments  of  fine  sand,  silt,  and  clay  in  the  quiet  waters 
of  extensive  lakes.  The  parent  material  was  not  confined  to  basaltic 
formations,  but  included  a  variety  of  rocks.  In  eastern  Oregon  and 
Washington  and  northern  Idaho  occur  also  extensive  deposits  of 
eolian  or  loessial  material  derived  from  a  wide  variety  of  rocks 
and  consisting  of  fine  unstratified  homogeneous  deposits  which  have 
probably  filtered  from  a  dust-laden  atmosphere  and  have  deeply  bur- 
ied the  basaltic  plains.  In  extensive  areas  of  the  Snake  River  and 
Columbia  River  plains  another  group  of  eolian  deposits  occurs. 
These  are  of  coarser  sandy  texture,  and  have  been  wind  blown  rather 
than  wind  borne,  being  transported  mainly  by  rolling  and  blowing 
of  the  mineral  fragments  along  the  surface. 

These  various  stream-laid,  lake-laid,  and  wind-laid  deposits  have 
in  some  cases  been  subject  to  weathering  in  place,  with  alteration  in 
their  mineral,  chemical,  and  physical  character,  and  with  correspond- 
ing changes  in  color,  texture,  and  structure,  accompanied  by  leaching, 
concentration  of  lime  or  other  minerals  from  percolating  solutions, 


20  IMPORTANT   SOILS    OF    THE    UNITED   STATES. 

•and  the  formation  of  heavy  subsoils  and  hardpans.  In  other  cases 
they  have  been  intrenched  or  dissected  by  later  streams,  eroded,  re- 
worked, and  redeposited  as  recent  stream  flood-plain  or  terrace 
deposits  or  as  alluvial-fan  accumulations,  often  with  an  admixture  of 
material  derived  from  rocks  foreign  to  the  region. 

The  soils  of  this  region,  as  developed  under  these  various  proc- 
esses, occupy  central  and  southeastern  Washington,  central  and 
eastern  Oregon,  that  portion  of  Idaho  exclusive  of  the  Rocky  Moun- 
tain Region,  and  a  small  portion  of  northeastern  California.  They 
constitute  about  4  per  cent  of  the  total  area  of  the  United  States. 

The  region  supports  about  1  per  cent  of  the  rural  population  and 
0.9  per  cent  of  the  farm  operators  of  the  United  States,  giving  seven 
operators  for  10,000  acres.  About  12.4  per  cent  of  the  region  is 
improved  land  in  farms,  which  is  equivalent  to  2  per  cent  of  the  total 
improved  farm  lands  in  the  United  States. 

Two  soils  have  been  selected  as  representative  of  this  region  in 
character  and  in  type  of  agricultural  development,  the  Walla  Walla 
silt  loam  of  the  loessial  material  and  the  Yakima  fine  sandy  loam  of 
the  recent  alluvial  flood-plain  and  terrace  material.  The  Walla 
Walla  soils  cover  about  9.3  per  cent,  and  the  Yakima  soils  about  6.9 
per  cent  of  the  area  surveyed  in  this  region.  The  types  selected  are 
the  predominating  soils  of  these  series. 

The  Walla  Walla  soils  are  of  brown  to  dark-brown  color,  with 
slightly  lighter  or  more  reddish  brown  subsoils,  and  underlain  by  a 
substratum  of  light-brown  or  yellowish-brown  fine  silty  material 
without  stratification  and  of  homogeneous  character.  This  material, 
which  may  be  somewhat  calcareous,  extends  to  the  underlying  bed- 
rock, usually  occurring  at  a  depth  of  many  feet.  The  soil  material  is 
derived  from  an  undetermined  though  wide  variety  of  rocks.  The 
soils  occupy  a  rolling  to  rather  hilly  region.  They  are  not  well 
adapted  by  conditions  of  climate  or  irrigation  to  fruit  culture,  but 
they  are  friable,  retentive  of  moisture,  and  usually  productive,  and 
with  related  series  of  soils  differing  only  in  color  are  the  great  wheat- 
growing  soils  of  the  Palouse  region  in  eastern  Washington  and  Ore- 
gon and  northern  Idaho. 

The  Yakima  soils  are  of  light-brown  to  medium-brown  color;  the 
subsoils  are  usually  friable,  not  heavier  than  the  surface  soil,  and 
underlain  by  a  porous  sand  and  gravel  substratum.  These  soils  occur 
as  recent  alluvial  deposits  in  stream  valleys.  The  parent  material  is 
derived  largely  from  basaltic  material,  but  material  derived  by 
erosion  from  adjacent  lake  sediments  or  from  more  remote  areas  of 
rocks  of  various  kinds  may  be  included.  These  soils  are  usually 
favorably  situated  with  regard  to  protection  from  frosts  and  means 
of  irrigation,  and  have  been  highly  developed  in  the  production  of 


IMPORTANT   SOILS   OF   THE   UNITED   STATES.  21 

choice  apples,  pears,  and  other  tree  fruits,  small  fruits,  cantaloupes, 
hops,  and  alfalfa. 

Pacific  Coast  Region. — The  Pacific  Coast  Region  covers  an  area 
of  consolidated  rocks.  Broadly,  it  is  of  mountainous  character,  with 
narrow  to  broad  structural  valleys  or  basins.  The  areas  of  consoli- 
dated rocks  are  characterized  by  residual  soils  derived  from  weather- 
ing of  the  underlying  rock  in  place.  The  valleys  and  basins  are  par- 
tially filled  with  transported  soil  material  derived  from  the  residual 
soils  of  the  adjacent  mountains  and  deposited  in  different  ways  and 
under  varied  conditions.  Isolated  marginal  areas  of  marine  coastal 
plain  sediments  occur  along  the  coast. 

In  California  the  Sierra  Nevada  on  the  east  is  made  up  mainly  of 
metamorphosed  sedimentary  and  igneous  rocks  with  great  intrusions 
of  granite,  such  as  constitute  most  of  the  related  southern  California 
ranges.  The  Coast  Ranges  of  the  region  are  mainly  of  softer  sedi- 
mentary or  of  metamorphosed  sedimentary  rocks,  with  minor  igneous 
intrusions.  The  Klamath  Mountains  of  northern  California  and 
southern  Oregon  are  related  to  the  Sierra  Nevada,  and  the  Cascade 
Range,  extending  from  northern  California  to  the  international 
boundary,  is  mainly  of  basaltic  or  andesitic  volcanic  origin.  The 
transported  soil  material  derived  from  these  various  sources  has  ac- 
cumulated through  agencies  of  deposition  by  melting  glacial  ice, 
by  running  water,  in  wTaters  of  inland  seas,  or  as  coastal  beach  and 
marine  shore  deposits  which  have  since  been  elevated,  and  by  winds. 
The  deposits  in  the  seas  occupying  the  inland  basins  include  both  fresh 
and  salt  water  sediments;  the  stream-laid  deposits  include  glacial 
and  nonglacial  sediments  and  those  distributed  both  as  low7,  broad  to 
steeply  sloping  alluvial  fans  and  as  flood-plain  and  river-terrace 
accumulations. 

Much  of  this  transported  material  has  since  deposition  been 
weathered  in  place,  with  the  development  of  more  pronounced  colors, 
leaching,  concentration  of  lime,  and  the  formation  of  heavy  subsoils 
and  hardpans.  This  older  material  is  also  now  undergoing  degrada- 
tion or  removal  by  erosion,  and  much  has  been  reworked  and  redis- 
tributed as  recent  alluvial  material  by  streams.  Modification  and 
redistribution  of  both  the  older  and  younger  deposits  by  winds  is 
also  taking  place  locally. 

The  soils  of  this  region  cover  portions  of  Washington,  Oregon, 
and  California  lying  west  of  the  eastern  base  of  the  Cascades,  the 
Sierra  Nevada  Mountains,  and  associated  southern  California  moun- 
tain ranges  marking  the  western  boundary  of  the  southwestern  desert 
areas.  They  cover  about  5.7  per  cent  of  the  total  area  of  the  United 
States. 

The  Pacific  Coast  Region  supports  about  2.7  per  cent  of  the  rural 
population  of  the  United  States,  and  2.1  per  cent  of  the  farm  opera- 


22  IMPOETANT  SOILS  OF   THE   UNITED   STATES. 

tors,  giving  12  operators  per  10,000  acres.  The  11.4  per  cent  of  the 
region  in  improved  farms  is  equivalent  to  2.6  per  cent  of  the  im- 
proved farm  lands  of  the  United  States. 

Five  soils  have  been  selected  as  the  most  important  of  the  region. 
Four  of  these,  the  Fresno  sand,  Placentia  loam,  San  Joaquin  sandy 
loam,  and  Stockton  clay  adobe,  represent  the  weathered,  older  valley 
filling  material,  characterized  by  heavy  subsoils  or  hardpans.  The 
recent  alluvial  soils  are  represented  by  the  Hanford  fine  sandy  loam. 
These  are  the  dominant  types  of  their  respective  series.  Of  the 
area  thus  far  surveyed  in  this  region,  the  Fresno  series  comprises 
6.02  per  cent,  the  Placentia  series  2.98  per  cent,  the  San  Joaquin 
series  5.66  per  cent,  the  Stockton  series  0.95  per  cent,  and  the  Han- 
ford  series  5  per  cent. 

The  Fresno  soils  are  brown  to  light  brown  in  color,  with  variations 
of  light  grayish  brown  or  light  gray  under  dry  field  conditions.  The 
subsoils  are  of  similar  or  slightly  lighter  color,  usually  of  heavier 
texture,  except  in  the  sandier  members,  are  sometimes  calcareous, 
and  in  the  types  of  medium  and  heavy  texture  have  a  gray  to 
light-brown  hardpan.  The  series  occupies  old  alluvial-fan  deposits 
of  flat  to  gently  sloping  and  frequently  of  hummocky  or  irregular 
surface.  The  material  is  derived  from  a  variety  of  rocks,  has  been 
weathered  in  place  since  deposition,  and  in  case  of  the  lighter  mem- 
bers is  sometimes  modified  by  winds.  The  heavier  soils  usually  are 
poorly  drained,  and  injurious  accumulations  of  alkali  salts  occur, 
but  the  lighter  members  are  extensively  irrigated  and  highly  devel- 
oped in  the  production  of  raisins,  sweet  wine  and  table  grapes, 
peaches,  apricots,  watermelons,  and  alfalfa. 

The  Placentia  soils  and  subsoils  are  red  or  brownish  red  in  color 
under  field  conditions,  the  dry  samples,  however,  usually  appearing 
reddish  brown.  The  subsoils  are  generally  of  more  pronounced 
color  and  of  heavy,  compact  character,  but  without  true  cemented 
hardpan.  The  material  is  low  in  humus,  is  not  calcareous,  is  de- 
rived mainly  from  granitic  rocks,  and  occurs  mainly  as  old  weathered, 
well-drained,  and  frequently  eroded  alluvial-fan  deposits.  Where 
capable  of  irrigation,  the  Placentia  soils  have  in  southern  California 
become  the  principal  orange  and  other  other  citrus  fruit  soils  of  the 
types  derived  from  the  older  valley-filling  material. 

The  San  Joaquin  soils,  like  the  Placentia  soils,  are  red  or  brownish 
red  under  moist  field  conditions,  but  air-dry  samples  are  more  nearly 
reddish  brown.  The  subsoils  are  heavy  and  compact,  with  a  ce- 
mented clay-iron  hardpan  which  is  impenetrable  to  subsoil  waters 
and  the  roots  of  ordinary  field  and  fruit  crops.  These  soils  occupy 
old  valley  plains,  are  frequently  poorly  drained,  and  are  utilized 
mainly  for  the  production  of  grains  under  dry-farming  systems. 


IMPORTANT   SOILS   OF   THE   UNITED   STATES.  23 

The  Stockton  soils  are  dark  gray  or  black  and  high  in  organic  mat- 
ter, with  black  to  dark-brown,  heavy,  compact  upper  subsoils  which 
rest  upon  yellowish-brown,  more  friable,  calcareous  deeper  subsoils 
containing  calcareous  nodules  and  discontinuous  layers  of  calcareous 
hardpan.  The  material  is  derived  from  a  wide  variety  of  rocks. 
These  soils  occupy  low,  flat  valley  plains  or  lower  extremities  of 
alluvial  fans  of  poorly  developed  drainage,  and  are  predominantly 
of  heavy  texture  and  compact,  adobelike  structure.  Owing  to  their 
physical  character  and  position  they  are  particularly  well  suited 
to  the  growing  of  rice  under  irrigation,  and  are  otherwise  utilized 
mainly  for  the  production  of  other  grains  and  for  general  farming. 

The  Hanford  soils  are  brown,  with  brown,  friable  subsoils,  not 
usually  heavier  in  texture  than  the  surface  soils.  They  consist  of 
recent  alluvial-fan,  river  flood  plain,  and  low  recent  stream  deposits 
which  have  not  been  weathered  sensibly  since  deposition.  The  mate- 
rial is  derived  mainly  from  granitic  rocks  and  usually  is  noticeably 
micaceous.  These  soils  are  of  extensive  occurrence,  usually  favorably 
situated  for  irrigation,  and  are  widely  utilized  for  intensively  culti- 
vated citrus  and  deciduous  fruits,  grapes,  small  fruits,  and  truck 
crops.  The  growing  of  alfalfa  and  general  farming  are  also  im- 
portant pursuits. 

Rocky  Mountain  Region, — The  Rocky  Mountain  Region  covers  an 
area  in  which  the  soil-forming  material  is  derived  by  weathering  in 
place  of  quartz-bearing  crystalline  rocks  of  igneous  and  metamorphic 
character,  such  as  granite  and  gneiss,  and  of  later  effusive  volcanic 
flows  of  basalt  and  other  lavas,  and  of  sedimentary  and  metamor- 
phosed sedimentary  rocks,  including  sandstone,  shale,  limestone, 
and  quartzite.  The  original  residual  material  has,  in  many  por- 
tions of  the  region,  been  acted  upon  and  modified  by  agencies  of 
transportation  and  by  further  weathering  in  place. 

The  agencies  of  transportation  consist  of  ice,  wind,  and  water, 
giving  rise  to  limited  areas  of  ice-laid  or  glacial  soils  in  the  northern 
and  in  the  higher  mountain  portions  of  the  region,  to  areas  of  eolian 
soils  occurring  upon  plains  and  in  river  valleys,  and  to  large  and 
important  areas  of  water-laid  soils  occupying  the  greater  part  of 
the  valleys.  Some  of  this  water-laid  material  has  been  deposited  by 
intermittent  or  fluctuating  streams,  often  torrential,  emerging  from 
mountain  canyons,  and  now  forms  extensive  alluvial  fans.  Some  of 
it  has  been  deposited  as  food-plain  and  river-terrace  deposits,  and 
some  has  been  discharged  into  the  waters  of  lakes  and  deposited  and 
reasserted  to  some  extent  by  waves  and  cu'rrents.  Some  of  these 
sediments  may  have  been  of  glacial  origin,  and  much  of  the  material 
has  been  weathered  in  place  until  it  has  lost  to  a  certain  extent  its 
original  character  and  has  been  eroded  and  entrenched  by  the  streams 


24  IMPORTANT   SOILS   OF    THE   UNITED  STATES. 

of  younger  valleys.  Owing  to  predominant  conditions  of  topog- 
raphy, depth  of  soil  material,  transportation,  and  of  climate  and  irri- 
gation, the  agricultural  soils  of  the  region  are  limited  mainly  to  the 
soils  derived  from  the  transported  material. 

The  soils  of  this  region  cover  northeastern  Washington,  northern 
Idaho,  and  western  Montana,  and  extend  southward  across  the  Rocky 
Mountain  Cordilleran  and  Plateau  districts  of  eastern  and  southern 
Utah,  western  Colorado,  and  into  southern  Arizona  and  New  Mexico. 
They  thus  cover  a  belt,  from  some  200  to  600  miles  wide,  extending 
nearly  the  whole  width  of  the  United  States.  They  form  14  per  cent 
of  the  total  area  of  the  country. 

This  region  contains  1.8  per  cent  of  the  total  rural  population  of 
the  United  States  and  1.3  per  cent  of  the  farm  operators,  or  3  op- 
erators to  10,000  acres.  Improved  land  in  farms  covers  2.6  per  cent 
of  the  region  and  constitutes  1.4  per  cent  of  the  improved  farming 
lands  in  the  United  States. 

Two  soils  have  been  selected  as  the  dominant  soils  of  their  series 
und  the  more  important  soils  of  the  region — the  Mesa  loam  of  the 
older,  weathered  valley  filling  material  and  the  Billings  fine  sandy 
loam  of  the  recent  alluvial  deposits.  The  Mesa  series  comprises  4.01 
per  cent  and  the  Billings  series  3.19  per  cent  of  the  area  surveyed  in 
the  Rocky  Mountain  Region. 

The  Mesa  soils  are  of  light  pinkish-red  or  grayish-red  to  light 
brownish  red  color,  with  lighter  gray  or  pinkish-gray,  calcareous 
subsoils,  which  are  usually  heavier  in  texture  and  more  compact  than 
the  surface  material.  The  subsoil  rests  upon  a  gravelly,  calcareous 
substratum,  often  partially  cemented.  The  organic-matter  content  is 
low,  but  the  soils  are  retentive  of  moisture.  These  soils  are  most 
typically  and  extensively  developed  in  the  filled  and  eroded  valleys 
of  western  Colorado,  occupying  old  valley  terraces  or  "  mesa  lands  " 
of  smooth  or  gently  sloping  surface  except  about  eroded  margins. 
They  usually  require  irrigation  for  successful  development,  but 
where  irrigated  have  been  extensively  utilized  for  the  production  of 
apples  and  peaches  and  of  alfalfa,  sugar  beets,  and  general  farm 
crops.  Their  topographic  position  insures  to  a  great  extent  freedom 
from  poor  drainage,  alkali,  and  destructive  frosts. 

The  Billings  soils  and  subsoils  are  of  light-gray  or  light  grayish 
brown  to  brownish  gray  color.  There  is  usually  but  little  differ- 
ence in  the  character  of  the  soil  and  subsoil,  but  the  subsoil  rests 
upon  a  substratum  of  stratified  stream-laid  deposits  of  variable 
and  alternating  texture,  which  may  closely  approach  the  surface. 
Both  surface  soil  and  subsoil  may  be  more  or  less  calcareous.  These 
soils  consist  of  recent  alluvial  deposits  derived  predominantly  from 
shales,  sandstones,  and  impure  limestones.  They  are  of  widespread 
occurrence  in  the  valleys  of  the  larger  streams  draining  and  travers- 


IMPORTANT   SOILS   OF    THE    UNITED   STATES.  25 

ing  the  areas  of  sedimentary  rocks.  They  occur  in  stream  flood 
plains  and  on  lower  terraces  and  low,  broad  local  alluvial  fans.  Un- 
like the  Mesa  series,  they  have  not  been  sensibly  weathered  or  oxi- 
dized in  place,  have  not  developed  as  much  color,  and  have  charac- 
teristically heavy  subsoils.  The  heavier  members  are,  however,  often 
of  compact  structure  and  are  frequently  subject  to  poor  drainage 
condition  and  the  accumulation  of  alkali  salts.  Lower  lying  bodies 
are  in  many  cases  affected  by  overflow.  Climatic  and  drainage  condi- 
tions are  less  favorable  to  fruit  culture  than  with  the  Mesa  soils  and 
the  series  is  more  extensively  utilized  for  the  production  of  alfalfa, 
stock  raising,  and  the  production  of  grains,  sugar  beets,  and  truck 
crops  and  vegetables,  though  fruit  is  grown  to  some  extent. 

Arid  /Southwest  JRegion. — The  Arid  Southwest  Region  is  predomi- 
nantly a  series  of  alluvial  fans.  It  covers  an  area  in  which  the  soil 
material  has  been  derived  mainly  from  crystalline  rocks  of  granitic 
or  gneissic  character,  but  in  part  also  from  more  recent  lava  flows, 
mainly  of  andesite  and  rhyolite,  and  from  sedimentary  and  meta- 
morphosed sedimentary  rocks. 

This  soil  material  has  been  transported  mainly  by  intermittent  or 
shifting  fluctuating  streams  and  by  surface  wash.  The  greater  part 
has  been  distributed  as  sloping  alluvial-fan  deposits  of  streams  of 
infrequent  but  torrential  flow  which  debouch  from  mountain  canyons 
upon  the  desert  plains  of  structural  valleys.  From  the  upper  sandy 
and  gravelly  margins  of  these  debris  slopes  rise  half  buried  outlying 
isolated  mountain  masses  and  hills  covered  with  shallow  and  rocky, 
nonirrigable  residual  soils.  The  lower  extremities  of  the  fans  or 
alluvial  slopes  occurring  farther  out  in  the  valleys  become  flatter 
and  comprise  finer  material. 

The  few  large  streams  having  their  source  under  less  arid  condi- 
tions and  traversing  the  region  have  given  rise  to  areas  of  flood  plain 
and  terrace  deposits  which  occur  in  the  wide,  shallow  stream  valleys, 
and  some  of  the  finer  sediments  borne  by  streams  or  by  gradually 
extending  surface  wash  have  been  deposited  in  the  waters  of  lakes 
occupying  the  lower  portions  of  the  valley  basins.  Some  of  these 
alluvial-fan,  river-laid,  and  lake-laid  deposits  have  since  been  further 
modified  and  transported  by  winds.  In  some  cases  the  soils  arc 
characterized  by  the  rocks  from  which  they  originally  came,  and 
they  may  have  a  single  source  or  a  number  of  sources,  while  in  others 
they  have  been  so  affected  by  processes  of  weathering  in  place  subse- 
quent to  their  deposition  that  they  have  lost  more  or  less  of  their 
original  lithological  and  physical  characteristics.  Owing  to  condi- 
tions of  arid  climate,  transportation,  and  source  of  water  supply  for 
irrigation,  the  agriculture  of  the  region  is  confined  mainly  to  the  older 
valley  filling  and  recent  alluvial  soils  of  the  principal  stream  valleys. 


26  IMPORTANT  SOILS   OF   THE   UNITED  STATES. 

The  soils  of  this  region  occupy  southern  Arizona  and  New  Mexico 
and  extend  into  western  Texas  and  southeastern  California,  and 
cover  an  area  some  175  miles  in  average  width  and  extending  ap- 
proximately 800  miles  in  a  northwesterly  and  southeasterly  direc- 
tion. They  constitute  4.2  per  cent  of  the  area  of  the  United  States. 

The  region  supports  0.5  per  cent  of  the  rural  population  of  the 
United  States  and  0.3  per  cent  of  the  farm  operators,  or  about  3 
operators  to  10,000  acres.  Approximately  1.6  per  cent  of  the  region 
consists  of  improved  farm  land,  which  is  about  0.3  per  cent  of  the 
improved  land  in  farms  in  the  United  States. 

Two  soils,  the  Imperial  fine  sandy  loam,  of  the  older  deposits,  and 
the  Gila  fine  sandy  loam,  of  the  recent  alluvial  deposits,  have  been 
selected  as  representing  the  prevailing  type  of  agriculture,  and  these 
are  the  dominating  soils  of  their  respective  series.  The  Imperial 
series  covers  30.85  per  cent,  and  the  Gila  series  24.01  per  cent  of 
the  area  surveyed  in  this  region. 

The  Imperial  series  includes  light-brown  soils  and  subsoils,  usually 
of  peculiar  purplish  tint,  with  heavy,  compact,  deeper  subsoils,  and 
substrata.  The  organic-matter  content  is  low  and  the  soils  are 
sometimes  subject  to  deficient  drainage  and  the  accumulation  of 
alkali.  They  are  derived  from  old  lake  sediments,  the  superficial 
surface  material  of  which  has,  however,  to  a  greater  or  less  extent, 
been  modified  by  later  distribution  by  streams  and  winds.  Under 
favorable  conditions  of  irrigation  they  have  in  the  Imperial  Valley 
of  California  been  highly  developed  and  are  extensively  utilized  for 
the  production  of  cotton,  cantaloupes,  and  alfalfa,  and  for  general 
farming. 

The  Gila  series  includes  light-brown  soils  and  subsoils,  frequently 
of  pinkish  or  purplish  tint  and  quite  similar  in  color  to  the  Imperial 
soils.  The  subsoils  are  variable  in  texture.  They  are  underlain 
by  or  include  porous  sandy  and  gravelly  material.  Lower  lying 
areas  are  subject  to  overflow  and  to  poor  drainage  and  alkali,  but 
are  usually  capable  of  drainage  and  reclamation.  These  soils  consist 
of  recent  alluvial  deposits  occurring  mainly  in  stream  valleys  and 
bottoms.  Where  irrigable  they  are  highly  valued  for  the  production 
of  truck  crops,  alfalfa,  and  tree  and  small  fruits,  and  for  general 
farming.  They  are  most  extensive  and  important  in  the  Gila,  Salt, 
Rio  Grande,  and  Colorado  River  Valleys. 

Great  Basin  Region, — In  the  Great  Basin  Region  the  soil-forming 
material  is  dominated  by  deposits  laid  down  in  the  waters  of  lakes 
which  formerly  covered  the  valley  basins  but  have  since  receded  or 
disappeared.  The  material  has  been  derived  from  a  variety  of 
rocks,  consisting  mainly  of  basalt,  rhyolite,  diorite,  and  other  vol- 
canic effusives  and  intrusives,  and  of  limestone  and  other  sedimenta- 
ries  and  metamorphosed  sedimentaries,  and  has  been  borne  to  the 


IMPORTANT  SOILS  OF   THE  UNITED  STATES.  27 

lake  basins  in  the  waters  of  streams  which  at  present  have  no  other 
outlet.  The  coarser  material  was  deposited  about  the  margins  of  the 
lakes  and  later  appeared  as  elevated  gravelly  terraces  with  the  pro- 
gressive evaporation  of  the  waters,  the  finer  material  was  swept 
farther  out  by  currents  and  deposited  as  stratified  beds  of  silt  and 
clay  in  more  remote  and  flatter  portions  of  the  basins,  in  some  of 
which  remnants  of  the  earlier  Quarternary  lakes  persist. 

The  larger  areas  of  these  deposits  have  been  entrenched  by  streams, 
drained,  and  weathered  in  place,  with  accompanying  modification 
through  leaching  and  concentration  of  lime  or  other  mnieral  deposits, 
through  oxidation  and  consequent  changes  in  color,  and  through  the 
formation  of  heavy  subsoils  or  hardpans.  About  the  margins  of  the 
present  lakes  occur  recent  unweathered  sediments  which  retain  their 
original  character  or  may  still  be  in  process  of  deposition  or  of  ex- 
posure by  further  recession  of  the  lake  waters. 

In  certain  cases  the  lake-laid  material  has  been  eroded,  reworked, 
and  redeposited  by  the  waters  of  streams,  and  other  portions  have 
been  modified  by  winds.  From  the  desert  lake  basins  of  the  structural 
valleys  making  up  most  of  the  region  rise  ranges  and  isolated  island- 
like  mountain  masses  covered  with  thin/  rocky,  and  usually  non- 
irrigable  residual  soils  derived  by  weathering  of  the  underlying  rock 
in  place.  The  mountain  bases  frequently  are  partly  buried  beneath 
later  shelving  or  sloping  accumulations  of  disintegrated  rock  debris, 
swept  from  the  mountain  sides  by  intermittent  torrential  streams 
and  distributed  as  extensive  alluvial  fans  and  debris  aprons  which 
extend  into  the  valley  basins  and  cover  portions  of  the  older  lake 
deposits. 

The  Great  Basin  soil  region  practically  coincides  with  the  physio- 
graphic province  of  the  same  name.  It  occupies  the  western  portion 
of  Utah,  practically  all  of  Nevada,  and  adjoining  portions  of  Oregon 
and  California,  and  constitutes  about  6.2  per  cent  of  the  area  of  the 
United  States. 

This  region  supports  0.3  per  cent  of  the  rural  population  of  the 
United  States,  and  0.2  per  cent  of  the  farm  operators,  or  approxi- 
mately 1  operator  to  10,000  acres,  and  1.6  per  cent  of  the  region  is 
in  improved  land,  constituting  0.4  per  cent  of  the  improved  farm 
lands  of  the  United  States. 

Two  soils  have  been  selected  as  representative  of  the  soils  of  the 
region — the  Trenton  loam  and  the  Carson  clay  loam.  These  soils  are 
the  predominating  types  of  their  series.  The  Trenton  series  con- 
stitutes 5.2  per  cent  and  the  Carson  series  1.4  per  cent  of  the  area 
surveyed  in  this  region. 

The  Trenton  series  comprises  brown  to  dark-brown  soils,  often 
with  a  somewhat  reddish  or  pinkish  hue  under  field  conditions.  The 
subsoils  are  of  somewhat  lighter  brown  or  gray  color,  often  of  light- 


28  IMPORTANT   SOCLS   OF    THE    UNITED   STATES. 

reddish  or  pinkish  tint,  calcareous,  and  underlain  by  stratified,  cal- 
careous lake  sediments  of  fine  texture  and  of  reddish-gray  or  light 
reddish-brown  color,  sometimes  mottled.  This  series  is  derived  from 
moderately  old  lake-laid  deposits  in  which  weathering  and  leaching 
have  taken  place  to  some  extent,  with  concentration  of  lime,  and 
usually  the  formation  of  heavy  subsoils.  Drainage  is  fair  to  some- 
what deficient.  The  soils  are  not  as  well  adapted  to  fruits  as  the 
soils  of  the  adjacent  higher  lying  areas  of  older  material,  but  are  ex- 
cellent sugar-beet  and  general  farming  soils.  They  occur  typically 
in  the  Cache  Valley,  Utah. 

The  Carson  soils  and  subsoils  are  dark  gray  or  drab  in  color,  high 
in  organic  matter,  and  less  highly  calcareous  than  the  Trenton  soils. 
The  heavy  types  predominate,  and  they  are  characterized  by  poor 
drainage  and  flat  surfaces.  These  soils  consist  of  the  most  recent  lake 
sediments  and  occur  about  the  margins  of  present  lakes  constituting 
remnants  of  earlier  and  more  extensive  bodies  of  water.  They  occur 
typically  in  the  Carson  and  Honey  Lake  Valleys  in  Nevada  and  Cali- 
fornia. The  Carson  soils  are  less  favorably  situated  with  regard  to 
frost  than  the  older  and  more  elevated  soils,  and  are  adapted  to 
extensive  rather  than  to  intensive  farming.  They  are  utilized 
mainly  for  native  hay,  grazing,  and  stock  raising  on  a  large  scale; 
and  for  general  farming. 

o 


